A storage area network (SAN) may be implemented as a high-speed, special purpose network that interconnects different kinds of data storage devices with associated data servers on behalf of a large network of users. Typically, a storage area network includes high performance switches as part of the overall network of computing resources for an enterprise. The storage area network may be clustered in close geographical proximity to other computing resources, such as mainframe computers, but may also extend to remote locations, such as other enterprise sites, for backup and archival storage using wide area network carrier technologies.
The various components of the SAN are interconnected by cables. A typical data-center contains many racks of interconnected equipment, such as switches. SAN administrators often wish to determine the cable connectivity between host devices, switches and target devices. For example, an administrator may wish to learn whether two devices are connected and if so, at which ports. Such a determination can be difficult for a large number of interconnected devices, and depending on the location of the devices relative to each other. For example, often cables are routed through false ceilings or floors to link devices in different parts of a building. In addition, cables are often bunched, for example in groups of 10 or 20 cables. Of course, the administrator generally cannot disconnect cables to determine connectivity without disrupting communication. Given these typical situations, it can be very difficult, if not impossible, to determine cable connectivity by manual inspection among the various devices of a SAN.